﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Web.Script.Serialization;
using System.Text;
using System.Data;
using System.IO;
using Newtonsoft.Json;
namespace DbCommon
{
    public class JsonHelper
    {
        public JsonHelper()
        {

        }
        /// <summary> 
        /// 对象转JSON 
        /// </summary> 
        /// <param name="obj">对象</param> 
        /// <returns>JSON格式的字符串</returns> 
        public static string ObjectToJSON(object obj)
        {
            JavaScriptSerializer jss = new JavaScriptSerializer();
            try
            {
                return jss.Serialize(obj);
            }
            catch (Exception ex)
            {
                throw new Exception("JSONHelper.ObjectToJSON(): " + ex.Message);
            }
        }
        /// <summary> 
        /// 数据表转键值对集合 
        /// 把DataTable转成 List集合, 存每一行 
        /// 集合中放的是键值对字典,存每一列 
        /// </summary> 
        /// <param name="dt">数据表</param> 
        /// <returns>哈希表数组</returns> 
        public static List<Dictionary<string, object>> DataTableToList(DataTable dt)
        {
            List<Dictionary<string, object>> list = new List<Dictionary<string, object>>();

            foreach (DataRow dr in dt.Rows)
            {
                Dictionary<string, object> dic = new Dictionary<string, object>();
                foreach (DataColumn dc in dt.Columns)
                {
                    dic.Add(dc.ColumnName, dr[dc.ColumnName]);
                }
                list.Add(dic);
            }
            return list;
        }

        /// <summary> 
        /// 数据集转键值对数组字典 
        /// </summary> 
        /// <param name="dataSet">数据集</param> 
        /// <returns>键值对数组字典</returns> 
        public static Dictionary<string, List<Dictionary<string, object>>> DataSetToDic(DataSet ds)
        {
            Dictionary<string, List<Dictionary<string, object>>> result = new Dictionary<string, List<Dictionary<string, object>>>();

            foreach (DataTable dt in ds.Tables)
                result.Add(dt.TableName, DataTableToList(dt));

            return result;
        }

        /// <summary> 
        /// 数据表转JSON 
        /// </summary> 
        /// <param name="dataTable">数据表</param> 
        /// <returns>JSON字符串</returns> 
        public static string DataTableToJSON(DataTable dt)
        {
            return ObjectToJSON(DataTableToList(dt));
        }

        /// <summary>
        /// DataTable转换为JSON
        /// </summary>
        /// <param name="dt">DataTable源</param>
        /// <param name="dtName">JSON属性命名</param>
        /// <returns>JSON数据</returns>
        public static string DataTableToJSON(DataTable dt, string dtName)
        {
            StringBuilder sb = new StringBuilder();
            StringWriter sw = new StringWriter(sb);

            using (JsonWriter jw = new JsonTextWriter(sw))
            {
                JsonSerializer ser = new JsonSerializer();
                jw.WriteStartObject();
                jw.WritePropertyName(dtName);//属性名称
                jw.WriteStartArray();
                foreach (DataRow dr in dt.Rows)
                {
                    jw.WriteStartObject();

                    foreach (DataColumn dc in dt.Columns)
                    {
                        jw.WritePropertyName(dc.ColumnName);
                        ser.Serialize(jw, dr[dc].ToString());
                    }

                    jw.WriteEndObject();
                }
                jw.WriteEndArray();
                jw.WriteEndObject();

                sw.Close();
                jw.Close();
            }

            return sb.ToString();
        }

        /// <summary> 
        /// JSON文本转为对象,泛型方法 
        /// </summary> 
        /// <typeparam name="T">类型</typeparam> 
        /// <param name="jsonText">JSON文本</param> 
        /// <returns>指定类型的对象</returns> 
        public static T JSONToObject<T>(string jsonText)
        {
            JavaScriptSerializer jss = new JavaScriptSerializer();
            try
            {
                return jss.Deserialize<T>(jsonText);
            }
            catch (Exception ex)
            {
                throw new Exception("JSONHelper.JSONToObject(): " + ex.Message);
            }
        }
        /// <summary> 
        /// 将JSON文本转换为数据表数据 
        /// </summary> 
        /// <param name="jsonText">JSON文本</param> 
        /// <returns>数据表字典</returns> 
        public static Dictionary<string, List<Dictionary<string, object>>> TablesDataFromJSON(string jsonText)
        {
            return JSONToObject<Dictionary<string, List<Dictionary<string, object>>>>(jsonText);
        }

        /// <summary> 
        /// 将JSON文本转换成数据行 
        /// </summary> 
        /// <param name="jsonText">JSON文本</param> 
        /// <returns>数据行的字典</returns> 
        public static Dictionary<string, object> DataRowFromJSON(string jsonText)
        {
            return JSONToObject<Dictionary<string, object>>(jsonText);
        }
        ///// <summary>
        ///// 将dictionary数组转为json文本
        ///// </summary>
        ///// <param name="dictionary"></param>
        ///// <returns></returns>
        //public static string DictionaryToJson(Dictionary<string,object>[] dictionary)
        //{
        //    StringBuilder JsonTxt = new StringBuilder();
        //    foreach (Dictionary<string, object> dic in dictionary)
        //    {
        //        JsonTxt.Append("{");
        //        foreach (var item in dic)
        //        {
        //            JsonTxt.AppendFormat("\"{0}\"", item.ToString());
        //        }
        //        JsonTxt.Append("}");
        //    }
        //    return JsonTxt.ToString();
        //}
    }
}
